All terrain vehicle with driver and passenger seating configuration

ABSTRACT

An all terrain vehicle (“ATV”) with a frame and two front wheels and two rear wheels suspended from the frame is disclosed. The front wheels define a front axis and the rear wheels define a rear axis. The front axis and the rear axis define a wheelbase between 52 to 72 inches. The ATV has a straddle-type seat supported by the frame with a main seat portion for a driver and a secondary seat portion, rearward of the main portion, for a passenger. The straddle-type seat is constructed and arranged such that, in use, a combined center of gravity of the ATV, with the driver sitting in a standard riding position on the main seat portion and the passenger sitting in a standard riding position on the secondary seat portion, is disposed in front of the rear axis by at least 22 inches.

CROSS-REFERENCE

[0001] This application is a Divisional of U.S. Utility patentapplication Ser. No. 10/292,813, titled “ATV WITH IMPROVED DRIVERPOSITIONING AND/OR MULTI PASSENGER CAPACITY,” filed on Nov. 13, 2002,which is a continuation-in-part of U.S. Utility patent application Ser.No. 09/950,926 titled “CARGO CARRYING COMPARTMENTS OF AN ALL TERRAINVEHICLE,” filed on Sep. 13, 2001, the contents of both of which areincorporated herein by reference.

[0002] Through application Ser. No. 09/950,926, this application claimsfurther priority to U.S. Provisional Patent Application No. 60/232,572titled “CARGO CARRYING COMPONENTS OF AN ALL TERRAIN VEHICLE,” filed onSep. 13, 2000, which is incorporated herein by reference.

[0003] Through application Ser. No. 10/292,813, this application alsoclaims priority to U.S. Provisional Patent Application No. 60/331,252titled “ATV WITH IMPROVED DRIVER POSITIONING AND/OR MULTI PASSENGERCAPACITY,” filed on Nov. 13, 2001, which is incorporated herein byreference.

[0004] Through application Ser. No. 10/292,813, this application alsoclaims priority to U.S. Provisional Patent Application No. 60/393,114titled “ATV WITH IMPROVED DRIVER POSITIONING AND/OR MULTI PASSENGERCAPACITY,” filed on Jul. 3, 2002, which is incorporated herein byreference.

[0005] Through application Ser. No. 10/292,813, this application alsoclaims priority to U.S. Provisional Patent Application No. 60/384,822titled “ATV WITH IMPROVED DRIVER POSITIONING AND/OR MULTI PASSENGERCAPACITY,” filed on Jun. 4, 2002, which is incorporated herein byreference.

[0006] This application also claims priority to U.S. Provisional PatentApplication No. 60/475,511 titled “ATV WITH IMPROVED DRIVER POSITIONINGAND/OR MULTI PASSENGER CAPACITY,” filed on Jun. 4, 2003, which isincorporated herein by reference.

FIELD OF THE INVENTION

[0007] This invention relates to all-terrain vehicles (ATVs), and inparticular ATVs in which two riders (a driver and a passenger) can beaccommodated. The present invention also relates to the seat positioningof the driver and/or passenger on the ATV.

BACKGROUND OF THE INVENTION

[0008] Conventionally, the term ATV or all-terrain vehicle has beenlimited to straddle-seat, wheeled vehicles that are constructed toaccommodate just one rider/driver. The Consumer Product SafetyCommission uses the one-rider limitation to define “ATV” due to thebelief that straddle-seat, wheeled vehicles could not safely accommodatemore than one rider.

[0009] As illustrated in FIGS. 11A and 11B, despite numerous warningsthat a conventional ATV 1000 is designed for just one driver 1010, inpractice, a passenger 1020 often rides on the one-person ATV 1000.Placing two riders 1010, 1020 on the one-rider ATV 1000 creates severalproblems. First, as illustrated in FIG. 11A, because the seat of theone-person ATV 1000 is designed to accommodate just one rider, thepassenger 1020 must uncomfortably squeeze onto the ATV's one-person seatbetween the driver 1010 and a rear rack 1030. Second, as illustrated inFIG. 11B, a footrest 1040 of the ATV 1000 is similarly designed to onlybe long enough to accommodate the feet of the one intended rider 1010.The wheelbase of the ATV 1000 limits the space between front and rearfenders 1050, 1060. Consequently, the driver 1010 and passenger 1020must uncomfortably share the one-person footrest 1040. Third, becausethe driver 1010 and passenger 1020 must be so tightly squeezed together,the legs of the passenger 1020 inhibit the ability of the driver 1010 tomove, while the body of the driver 1010 inhibits the ability of thepassenger 1020 to move. Such limited mobility disadvantageously limitsthe abilities of both riders 1010, 1020 to actively position themselves(e.g., lean into curves or slopes to stabilize the ATV 1000). Fourth, asshown in FIG. 11A, a center of gravity of the passenger 1020 islongitudinally positioned at, near, or even behind a rear wheel axis1070 of the ATV 1000 such that the back of the passenger 1020 isdisposed rearwardly of the rear wheel axis 1070. Such positioningdisadvantageously shifts the combined center of gravity of the ATV 1000and riders 1010, 1020 rearwardly, thereby increasing the risk of tippingthe ATV 1000.

[0010] As illustrated in FIGS. 12A and 12B, a conventional after-marketpassenger seat 1100 was developed in an attempt to provide a seat forthe passenger 1020 that can be attached to a conventional one-person ATVlike the ATV 1000. While the passenger seat 1100 provides morelongitudinal space for the passenger 1020, it suffers from many of thesame deficiencies encountered when the passenger 1020 rides on the ATV1000 without a passenger seat 1100 (as shown in FIGS. 11A and 11B).Furthermore, the seat 1100 creates additional problems for the ATV 1000and riders 1010, 1020. First, in order to give the passenger 1020 morelongitudinal space, the seat 1100 must be shifted far to the rear of theATV 1000. As illustrated in FIG. 12A, such positioning places the centerof gravity of the passenger 1020 well behind the rear wheel axis 1070 ofthe ATV 1000, which results in a combined ATV 1000 and rider 1010, 1020center of gravity that is farther behind the rear wheel axis as comparedto the dual-rider situation shown in FIGS. 11A and 11B. Second, becausethe passenger seat 1100 is positioned on top of the conventional rearrack 1030 of the ATV 1000, the passenger seat 1100 places the center ofgravity of the passenger 1020 in an elevated position on the ATV 1000,which further impairs the stability of both the passenger 1020 and theATV 1000. Furthermore, as illustrated in FIG. 12B, the extremelyelevated position of the seat 1100 relative to the driver's seat couldcause the knees of the passenger 1020 to interfere with the elbows ofthe driver 1010. Fourth, upwardly extending, rigid sides 1110 of theseat 1100 force the legs of the passenger 1020 laterally inwardly, whichfurther reduces the mobility of both the driver 1010 and the passenger1020 and impairs their abilities to actively position themselves duringoperation of the ATV 1000. Still further, placing the passenger seat1100 on top of the rear rack 1030 disadvantageously eliminates thestorage space on the rear rack 1030. While the passenger seat 1100 opensup to provide a small, internal storage compartment, such a storagecompartment is quite limited as compared to the large, open spaceprovided above the rear rack 1030 when the passenger seat 1100 isremoved.

[0011] Amacker (U.S. Pat. No. 4,247,030) discloses a passenger seat foran ATV that is similar to the after-market passenger seat 1100illustrated in FIGS. 12A and 12B and suffers from many of the sameshortcomings. As illustrated in FIG. 3 of Amacker, the passenger'scenter of gravity is disposed well behind the rear axis and thereforedisadvantageously increases the risk of rearward rollover of the ATV.Furthermore, both the passenger's legs and feet and the driver's legsand feet must be disposed at the same longitudinal position on the ATV,which causes the driver and the passenger to interfere with each other'smobility and thereby inhibit their ability to actively positionthemselves.

SUMMARY OF THE INVENTION

[0012] The inventors of the present invention determined that ifmultiple riders are going to ride ATVs that are designed for one riderdespite all contraindications and/or other warnings, then ATVs should beconstructed to safely accommodate multiple riders. Accordingly, throughthe present invention, the inventors resolved safety concerns of theindustry regarding multi-person ATVs.

[0013] Accordingly, one aspect of embodiments of the invention providesan ATV that can safely accommodate two riders (a driver and apassenger). For example, the wheelbase of the ATV can be extended (e.g.,by about 8″ to 12″ or more) compared to conventional ATVs such that thedriver is more centered between the front and rear wheels, which createsadditional space to accommodate an additional rider behind the driver.An advantage to this structure is that the driver's riding position ismore active and comfortable, and the passenger can be accommodated in asafe manner.

[0014] Another aspect of embodiments of the invention provides an ATV onwhich a single rider, i.e., the driver, can be placed in a position thatis more centered between the front and rear pairs of wheels, therebyimproving driver comfort and/or reducing the chances for roll-over ofthe ATV.

[0015] Another aspect of embodiments of the present invention provides atwo-person ATV that allows the driver and passenger to actively positionthemselves during operation of the ATV.

[0016] One additional aspect of the present invention provides an ATVwith a frame and only four wheels suspended from the frame. Two of thewheels are rear wheels and two of the wheels are front wheels. The frontwheels define a front axis and the rear wheels define a rear axis. Thefront axis and the rear axis define a wheelbase between 52 to 72 inches,and each of the wheels includes an ATV-type tire. The ATV has a powerunit for driving at least one of the wheels disposed on the frame and astraddle-type seat supported by the frame. The seat includes a main seatportion for a driver and a secondary seat portion, rearward of the mainportion, for a passenger. The ATV also has a steering member connectedto the frame that includes a handlebar for steering at least one of thewheels. The straddle-type seat is constructed and arranged such that, inuse, a combined center of gravity of the ATV, with the driver sitting ina standard riding position on the main seat portion and the passengersitting in a standard riding position on the secondary seat portion, isdisposed in front of the rear axis by at least 22 inches.

[0017] Still another aspect of the present invention provides an ATVwhere the straddle-type seat is constructed and arranged such that, inuse, the center of gravity is disposed in front of the rear axis by atleast 23 inches.

[0018] One additional aspect of the present invention provides an ATVwhere the straddle-type seat is constructed and arranged such that, inuse, the center of gravity is disposed in front of the rear axis by atleast 24 inches.

[0019] A further aspect of the present invention provides an ATV with aframe and only four wheels suspended from the frame. At least one of thewheels is a front wheel and at least one of the wheels is a rear wheel.The front wheel defines a front axis and the rear wheel defines a rearaxis. The ATV has a power unit for driving at least one of the wheelsdisposed on the frame and a straddle-type seat supported by the frame.The seat includes a main seat portion for a driver and a secondary seatportion, rearward of the main portion, for a passenger. The ATV also hasa steering member connected to the frame that includes a handlebar forsteering at least one of the wheels. The straddle-type seat isconstructed and arranged such that, in use, a combined center of gravityof the ATV, with the driver sitting in a standard riding position on themain seat portion and the passenger sitting in a standard ridingposition on the secondary seat portion, is disposed rearwardly of thefront axis by at least 21 inches.

[0020] One further aspect of the present invention provides an ATV wherethe straddle-type seat is constructed and arranged such that, in use,the center of gravity is disposed rearwardly of the front axis bybetween 24 and 45 inches.

[0021] Another aspect of the present invention provides an ATV where thestraddle-type seat is constructed and arranged such that, in use, thecenter of gravity is disposed in front of the rear axis by at least 30inches.

[0022] A further aspect of the present invention provides an ATV wherethe straddle-type seat is constructed and arranged such that, in use,the center of gravity is disposed in front of the rear axis by at least32 inches.

[0023] An additional aspect of the present invention provides an ATVwhere the straddle-type seat is constructed and arranged such that, inuse, the center of gravity is disposed in front of the rear axis by atleast 33 inches.

[0024] Another aspect of the present invention provides an ATV where thestraddle-type seat is constructed and arranged such that, in use, thecenter of gravity is disposed in front of the rear axis by between 34and 45 inches.

[0025] One additional aspect of the present invention provides an ATVwith a frame and only four wheels suspended from the frame. Two of thewheels are rear wheels and two of the wheels are front wheels. The frontwheels define a front axis and the rear wheels define a rear axis, andeach of the wheels includes an ATV-type tire. The ATV has a power unitfor driving at least one of the wheels disposed on the frame and astraddle-type seat supported by the frame including a main seat portionfor a driver and a secondary seat portion for the passenger. The ATValso has a steering member connected to the frame that includes ahandlebar for steering at least one of the wheels. The ATV has a centerof gravity and a ratio of a distance between the front axis and thecenter of gravity to a distance between the center of gravity and therear axis is greater than 1.05, greater than 1.07, greater than 1.09,greater than 1.1, greater than 1.11, and between 1.05 and 2.

[0026] Additional and/or alternative aspects of the embodiments of thepresent invention will be described in or apparent from the followingdescription of the preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

[0027]FIG. 1 is a left side view of an ATV according to a preferredembodiment of the present invention;

[0028]FIG. 2A is a perspective view of the rear, left side of the ATVshown in FIG. 1;

[0029]FIG. 2B is a rear view of the ATV shown in FIG. 1;

[0030]FIG. 3A is a perspective view of the top, left side of the ATVshown in FIG. 1;

[0031]FIG. 3B is a top left partial perspective view of the seat of theATV shown in FIG. 1;

[0032]FIG. 3C is a forward left partial perspective view of a backrestof the ATV shown in FIG. 1;

[0033]FIG. 3D is a right perspective view of the backrest of the ATVshown in FIG. 1;

[0034]FIG. 4A is a partial left side view of a left passenger grabhandle of the ATV shown in FIG. 1;

[0035]FIG. 4B is a partial top view of the left passenger grab handle ofthe ATV shown in FIG. 1;

[0036]FIG. 4C is a partial perspective view of the left passenger grabhandle of the ATV shown in FIG. 1;

[0037]FIG. 5A is a partial perspective view of the top and side of aleft footrest of the

[0038]FIG. 5B is a partial top perspective view of the left footrest ofthe ATV shown in FIG. 1;

[0039]FIG. 5C is a left side view of the left footrest of the ATV shownin FIG. 1;

[0040]FIG. 6 is a partial top view of the ATV shown in FIG. 1 with theseat removed;

[0041]FIG. 7 is a partial perspective view taken from the top, rear sideof the ATV shown in FIG. 1 with the seat removed;

[0042]FIG. 8 is a side view of the ATV shown in FIG. 1 with comparativecenters of gravity of various components of the ATV shown in FIG. 1 andof the conventional ATVs shown in FIGS. 11A-12B;

[0043]FIG. 9 is a partial cut away side view of the ATV shown in FIG. 1illustrating the power unit;

[0044]FIG. 10 is a partial perspective view of the ATV of FIG. 1 with aback rest and grab handles according to an alternative embodiment of thepresent invention;

[0045]FIG. 11A is a left side view of two riders riding a conventionalone-person ATV;

[0046]FIG. 11B is a forward left partial perspective view of the ridersand ATV shown in FIG. 11A;

[0047]FIG. 12A is a left side view of two riders riding a conventionalone-person ATV with an after market passenger seat attached thereto;

[0048]FIG. 12B is a forward left partial perspective view of the tworiders and ATV shown in FIG. 12A;

[0049]FIG. 13 illustrates a front elevational view of a standard rider;

[0050]FIG. 14 illustrates a side elevational view of the standard riderillustrated in FIG. 13; and

[0051]FIG. 15 is a left side view of a three person ATV according to analternative embodiment of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0052] FIGS. 1-9 show an ATV 100 according to a preferred embodiment ofthe present invention.

[0053] Throughout this description, unless otherwise expressly stated,all dimensions and relationships between elements are measured when theATV 100 is unloaded (i.e., without riders or baggage), has a full oilreservoir and tank of fuel, is on level ground, and is steered straightforward. Furthermore, unless otherwise indicated, the driver andpassenger have the weight and dimensions of a standard rider. Thestandard rider is a 50^(th) percentile human male who weighs 78 kg andhas the dimensions illustrated in FIGS. 13 and 14.

[0054] Throughout this description, the term ATV shall not be limited tothe conventional one-rider definition. Rather, the ATV 100 is stillreferred to as an ATV despite the fact that it is designed toaccommodate a driver and a passenger, and could be designed toaccommodate a driver and multiple passengers. Moreover, the ATV 100 isdesigned to comfortably accommodate just the driver as well.

[0055] As shown in FIG. 1, the ATV 100 includes a frame 102 thatsupports a pair of laterally-spaced, front wheels 105 and a pair oflaterally-spaced, rear wheels 110. The wheels 105, 110 are preferablyequally sized. The wheels preferably have a diameter of between about 20to 30 inches, and more preferably about 25 inches.

[0056] A wheelbase L, defined between the axes of rotation 107, 108 ofthe wheels 105, 110, respectively, is significantly longer than inconventional ATVs, and is preferably at least about 8 to 14 incheslonger than conventional ATV wheelbases. Preferably, the wheelbase isabout 10 to 12 inches longer than a standard ATV wheelbase.Specifically, the wheelbase L is preferably between 52 and 72 inches, ismore preferably between 55 and 65 inches, is even more preferablybetween 56 and 64 inches, and is even more preferably about 61 inches.As discussed in greater detail below, the elongated wheelbase L providesnumerous advantages over shorter conventional ATVs. These advantages mayinclude improved stability (less susceptibility to tipping or rolling),a more comfortable ride for the driver, the comfortable facilitation ofa seat for a passenger, active positioning of the driver and passenger,and reduced physical interference between the driver and passenger(i.e., via increased space for the driver and passenger and/or improveddriver and passenger mobility).

[0057] If greater than four wheels are provided on the ATV 100, thewheelbase L should be measured over the longest longitudinal spanbetween longitudinally adjacent axes. For example, if the ATV comprisessix wheels (three pairs of longitudinally spaced wheels), the wheelbaseL should be measured as the longer of (a) the distance between the frontand middle pairs of wheels, and (b) the distance between the middle andrearward pairs of wheels. Similarly, the front and rear wheels aredefined as the most-longitudinally-spaced-apart, longitudinally adjacentwheels. Consequently, “front” and “rear” wheels are defined relative toeach other and not relative to additional wheels that may also bepresent on the ATV.

[0058] The frame 102 is similar to a conventional ATV frame except thatthe frame 102 is extended to provide for the extended wheelbase L.Additional longitudinal structural elements may be added to the frame102 to strengthen the frame 102 over the extended gap between the wheels105, 110.

[0059] As shown in FIG. 1, the illustrated ATV 100 has a groundclearance G, which is similar to the ground clearance of conventionalATVs. The ground clearance G is defined by the vertical distance betweenthe ground and the lowest point on the frame 102 and is preferably about10 inches. However, as the wheelbase L elongates more and more, a changein ground clearance should be further considered. For example, if thewheelbase L is extended further, the ground clearance G should beincreased accordingly.

[0060] While the illustrated ATV 100 includes four wheels 105, 110, theATV 100 could alternatively include just three wheels (e.g., two rearwheels and a single front wheel or two front wheels and a single rearwheel). The front wheels 105 are suspended from the frame 102 by anappropriate front suspension 106, while the rear wheels 110 aresuspended from the frame 102 by an appropriate rear suspension 111. TheATV 100 includes a front bumper 115 and a rear bumper 120, and a frontrack 125 and a rear rack 130. A steering member, e.g., a pair ofhandlebars 134, is positioned just behind the front rack 125 and isoperably coupled to the front wheels 105 for steering purposes. The ATV100 includes front fenders 135 positioned above the front wheels 105 andrear fenders 137 positioned above the rear wheels 110.

[0061] As best illustrated in FIGS. 2A, 3A, 3C and 3D, the rear rack 130preferably comprises a plurality of interconnected, elongated members,which are preferably tubular. A rear member 130 a defines a rearward endof the rear rack 130. Similarly, side members 130 b define the outerlateral sides of the rear rack 130. A plurality of interior members 130c are also provided. It should be noted, however, that the structure ofthe rear rack 130 may be modified or the rear rack 130 may be eliminatedentirely without deviating from the scope of the present invention.

[0062] As illustrated in FIGS. 1, 2A, 3A, and 3B, the ATV 100 includes astraddle-type seat 139 that includes a main seat portion 140 and asecondary seat portion 145, which are connected together with atransition 142, which may provide a definite dividing line between themain and secondary seat portions 140, 145. Because the transition 142angles upwardly at approximately a 45 degree angle from the main seatportion 140 to the secondary seat portion 145, the transition 142generally provides a rear portion to the main seat portion 140 thattends to discourage the driver (i.e., the person sitting in the mainseat portion 140) from sliding rearwardly onto the secondary seatportion 145. Alternatively, a precise transition 142 may be eliminatedaltogether such that the main and secondary seat portions 140, 145together form a single, elongated, seat portion. Furthermore, thetransition may comprise a gap between the main and secondary seatportions 140, 145 such that the seat 139 has two separated portions.

[0063] Because the seat 139 is a two-person seat rather than aconventional one-person seat, a longitudinal length S of the seat 139formed between a forward end 140 a of the main seat portion 140 and arearward end 145 a of the secondary seat portion 145 a is significantlylonger than in the prior art. The length S is preferably between 30 and60 inches, is more preferably between 31 and 50 inches, is even morepreferably between 32 and 45 inches, and is even more preferably about37 inches.

[0064] The forward end 140 a of the seat 139 is defined as a point thatis slightly rearward (preferably 2-5 inches) of the rear end of thehandlebars 134. The forward end 140 a is also preferably disposedslightly forward or at the same longitudinal position as a heel stop 280of a footrest 250. Alternatively, if handlebars 134 are not provided ordo not reasonably define the forward end 140 a of the seat, the forwardend 140 a is defined as the forwardmost longitudinal position on theseat 139 that is designed to support any portion of the driver. Whilethe vast variation in conventional seat styles and shapes makes itdifficult to precisely define the forward end 140 a of a seat of everydifferent ATV without specific reference to each different seat style, aforward end of a seat of any ATV is readily determinable by one ofordinary skill in the art.

[0065] The rearward end 145 a of the seat 139 is defined by alongitudinal position of a forward surface 150 a of a back rest 150 ofthe ATV 100. However, if a back rest 150 is not provided on the ATV 100,the rearward end 145 a is quantitatively defined by the rearwardmostlongitudinal position on the seat 139 that is designed to support anyportion of the passenger.

[0066] As illustrated in FIG. 3D, the rearward end 140 a of the seatand/or the forward surface 150 a of the back rest 150 are preferablydisposed in front of a majority of the rear rack 130 so that they do notinterfere substantially with an open storage space provided on top ofthe rear rack 130. Accordingly, the rearward end 140 a and the forwardsurface 150 a are preferably disposed in front of a back side 130 a ofthe rear rack by a horizontal distance J, which is preferably between 5and 20 inches, is more preferably between 8 and 20 inches, is even morepreferably between 10 and 20 inches, and is even more preferably between14 and 20 inches. Because the back side 130 a of the rear rack isgenerally longitudinally aligned with a rear end of the ATV 100 as awhole, the rearward end 140 a and the forward surface 150 a bear thesame or similar relationship to the rear end of the ATV 100 as they doto the back side 130 a of the rear rack 130.

[0067] The main seat portion 140 accommodates a standard driver in astandard driving position while the ATV 100 is headed straight forward(i.e., to the left as illustrated in FIG. 1) on flat terrain. The mainportion 140 is positioned behind the front wheel axis 105 byapproximately the same longitudinal extent as a conventional rider seaton a conventional ATV.

[0068] As illustrated in FIGS. 1 and 3B, the main seat portion 140includes a main supporting range 140 b, which is defined on the uppersurface of the main seat portion 140 by a range of positions of a centerof the weight distribution on the main seat portion 140 of a driver whois sitting on the main seat portion 140 in an operating position.Accordingly, a center of the main supporting range is preferablylongitudinally disposed at the same point as the center of gravity 520of the driver (as shown in FIG. 8 and described in greater detailbelow). Of course, they could be different, if desired and depending onthe layout of the other components of the ATV 100 such as the engine215. The main supporting range 140 b is generally centered at a lateralcenter of the main seat portion 140 two thirds of the way back on themain seat portion 140 from the forward end 140 a (i.e. positioned behindthe forward end 140 a by two thirds of the longitudinal length of themain seat portion 140, which is defined generally as a distance Mbetween the forward end 140 a and the uppermost edge of thetransition/rear end 142 of the main seat portion 140). However, if themain seat portion 140 were shaped differently, the main supporting rangemay be located at a different relative position on the main seat portion140. The main supporting range 140 b preferably extends forwardly andrearwardly from its center by about 5 inches.

[0069] The center of the main supporting range 140 b is disposedlongitudinally rearwardly from the front wheel axis 107 by a distance T,which is preferably about 40-80% of the wheelbase L, is more preferablyabout 45-70% of the wheelbase L, and is even more preferably about55-65% of the wheelbase L. Conversely, the center of the main supportingrange 140 b is disposed in front of the rear wheel axis 108 by adistance that is preferably about 20-60% of the wheelbase L, is morepreferably about 30-55% of the wheelbase L, and is even more preferablyabout 35-45% of the wheelbase L. In absolute terms, the center of themain supporting range 140 b is positioned in front of the rear wheelaxis 108 by a distance L minus T, which is preferably between 21 and 30inches, and is more preferably about 21.6 inches. In an alternativeembodiment, distance L minus T is preferably about 22-30 inches, and ismore preferably about 24-27 inches.

[0070] As illustrated in FIG. 8 and discussed in greater detail below,the position of the main seat portion 140 places the driver closer tothe center of the wheelbase L than in conventional ATVs. Positioning thedriver close to the center of the wheelbase L of the ATV 100advantageously improves the driver's comfort. This positioning may alsoimprove the handling of the ATV 100 due to the driver's activepositioning.

[0071] The secondary portion 145 is designed to accommodate a passengerin a standard riding position. A secondary supporting range 145 b isdisposed on the secondary seat portion 145 and is defined in the samemanner as the main supporting range 140 a. A longitudinal length N ofthe secondary seat portion 145 is preferably 5% to 45% shorter than thelength M of the main seat portion 140, but could alternatively be thesame as the length M or even longer than the length M.

[0072] As illustrated in FIGS. 1-3D, a back rest 150 is provided behindthe secondary portion 145 to help support the back of the passenger. Theback rest 150 also deters additional unauthorized passengers from ridingthe ATV 100. The back rest 150 mounts on a post 152 that attaches to therear rack 130 or directly to the frame 102. As shown in FIG. 3D for theillustrated embodiment, the post 152 is bent at its lower end andincludes a slot 153 through which a plurality of bolts 154 extend toattach the post 152 to the rear rack 130. The slot 153 allows thelongitudinal position of the back rest 150 to be adjusted. However,other longitudinal adjustment mechanisms may alternatively be used.Although not shown, the back rest 150 is adapted to accommodate astandard sized passenger, but may also be vertically adjustable toaccommodate different sized passengers.

[0073] The post 152 (or some other part) of the backrest 150 ispreferably designed such that the backrest 150 may deflect forwardly andrearwardly by several inches (e.g., 3 to 4 inches) during normaloperation when subjected to a longitudinal load. This deflection enablesthe backrest 150 to more comfortably accommodate the passenger's back.The post 152 may comprise a resilient material such as spring steel thatcreates the desired flexibility.

[0074] While the illustrated back rest 150 utilizes just onecentrally-positioned support post 152, the back rest could be attachedto the ATV 100 in a variety of other manners as well. For example, FIG.10 illustrates an alternative back rest 160 that may mount onto the ATV100 instead of the back rest 150. The back rest 160 is mounted to theATV 100 via two laterally-spaced support posts 162 that extend betweenopposite lateral sides of the back rest 160 and a structural portion ofthe ATV 100 such as the frame 102 or the rear rack 130. As illustratedin FIG. 10, a forward back-supporting surface 160 a of the back rest 160arches rearwardly in its middle portion such that a middle of thesurface 160 a is disposed rearwardly of the lateral sides of the surface160 a.

[0075] A back-supporting forward surface 150 a is adapted to support andrest against a back of the passenger. The forward surface 150 a ispreferably disposed in front of the axis 108 of the rear wheels 110 by adistance B. However, the forward surface 150 a could alternatively bedisposed behind the rear axis 108 if other components are moved, thedanger of rollover is minimized, and/or the dynamic handling of the ATVis not significantly adversely affected. The distance B is preferablygreater than zero, is more preferably between ½ and 10 inches, and iseven more preferably between about ½ and 3 inches. Alternatively, thedistance B may preferably be between about 1 and 10 inches, and morepreferably between about 1 and 3 inches. Similarly, the forward surface150 a is preferably disposed in front of a majority of, if not all of,the rear rack 130. Accordingly, the back rest 150 does notsignificantly, if at all, interfere with the storage space above therear rack 130 (i.e., the rear rack 130 is usable even when the back rest150 is attached to the ATV 100). Furthermore, the forward surface 150 ais preferably disposed at generally the same longitudinal position alongthe ATV 100 as a rearward end 145 a of the secondary seat portion 145.Accordingly, the rearward end 145 a of the secondary seat portion 145and the forward surface 150 a preferably bear the same or similarlongitudinal relationships to the axis 108 and rear rack 130.

[0076] As shown in FIGS. 1 and 3B, a secondary supporting range 145 b ofthe secondary seat portion 145 is disposed farther forward relative tothe rear wheel axis 108 on the ATV 100 than the after-market passengerseat on conventional ATVs (as described above), which are disposedbehind the driver's seat. Accordingly, as illustrated in FIG. 8 anddiscussed in greater detail below, a passenger on the secondary seatportion 145 of the ATV 100 is positioned closer to the center of gravity500 of the ATV 100 than passengers on conventional aftermarket passengerseats of conventional ATVs. Placing the passenger closer to the centerof the wheelbase L of the ATV 100 improves the passenger's comfort andreduces the risk of roll-over. Furthermore, because the forwardpositioning of the secondary seat portion 145 places the center ofgravity 550 of the passenger between the front and rear wheel axes 107,108, the passenger's weight is more evenly distributed over thewheelbase L of the ATV 100 than in conventional aftermarket passengerseats, where a center of gravity 570 of a passenger mightdisadvantageously be positioned behind the rear wheel axis 108.

[0077] The secondary seat portion 145 should be disposed high enoughabove the rear wheel axis 108 that it does not interfere with the rearwheels 110 and/or rear fenders 137. Accordingly, the secondary seatingrange 145 b of the secondary seat portion 145 is preferably disposedhigher than the rear wheel axis 108 by a distance R. (see FIG. 1). Thedistance R is preferably between 20 and 35 inches, and is morepreferably about 25 inches. In an exemplary embodiment, if the wheels105, 110 have 26 inch diameters and the distance R is 25 inches, thesecondary seat portion 145 would be disposed above the ground by about38 inches.

[0078] The secondary seat portion 145 is disposed lower on the ATV 100than conventional aftermarket passenger seats on conventional ATVs. Thelower positioning is possible because the secondary seat portion 145 isdisposed in front of the rear rack 130 and/or rear wheels 110, insteadof directly over the rear wheels or even behind the rear wheels as inthe prior art. Accordingly, the rear wheels 110 and rear fenders 137interfere less with the secondary seat portion 145 than the rear wheelsand fender of a conventional ATV interfere with conventional aftermarketpassenger seats. As illustrated in FIG. 8 and discussed in greaterdetail below, because the secondary seat portion 145 is lower thanconventional aftermarket passenger seats, the center of gravity 550 of apassenger on the secondary seat portion 145 of the ATV 100 is lower thanthe center of gravity 570 of a passenger on a prior art passenger seat.Lowering the passenger's center of gravity 550 advantageously improvesthe passenger's comfort, as well as the performance of the ATV 100.

[0079] The main supporting range 140 b is disposed below the secondarysupporting range 145 b by a vertical height H. The height H ispreferably between 0 and 8 inches, is more preferably between 1 and 4inches, and is even more preferably about 2 inches. While the height His preferably greater than 1 inch, the height H should be limited. Ifthe height H is too large, the passenger's knees may interfere with theelbows of the driver and inhibit the driver's ability to steer the ATV100. To avoid this problem, the height H is preferably less than 8inches and is more preferably less than 4 inches. The height H mayalternatively be zero (or even negative) such that the main andsupporting ranges 140 b, 145 b are disposed at approximately equalheights.

[0080] As illustrated in FIGS. 1 and 3B, the center of the mainsupporting range 140 b is longitudinally spaced from the center of thesecondary supporting range 145 b by a distance Q, which is preferablyabout 8 to 20 inches, is more preferably about 12 to 17 inches. Thedistance Q provides adequate longitudinal space for both the driver andthe passenger such that the riders to not significantly interfere witheach other. The distance Q provides adequate longitudinal space for theriders to comfortably and actively position themselves.

[0081] As best illustrated in FIG. 3B, forward parts of both the mainand secondary seat portions 140, 145 taper laterally inwardly as theyprogress forwardly. Consequently, the forward part of the secondary seatportion 145 is preferably narrower than a rearward part of the main seatportion 140. The wider rearward parts of the seat portions 140, 145provide comfortable support for the riders while the narrower forwardparts of the seat portions 140, 145 provide the riders with greater legmobility that improves the riders' abilities to actively positionthemselves. For example, when making a left turn during operation of theATV, it is advantageous for the riders to be able to actively positionthemselves by shifting their weight to the left to stabilize the ATV100. In this situation, the inward taper of the forward parts of theright side of the seat portions 140, 145 enables the riders to betterposition themselves by comfortably angling their right legs to a greaterextent.

[0082]FIG. 6 is a partial top view of the ATV 100 with the seat 139removed to expose the power unit 215, which in this embodiment comprisesan internal combustion engine. The power unit 215 is operativelyconnected to at least one of the wheels 105, 110 via one or moredriveshafts 216 to power the ATV 100. The power unit 215 is preferablyoperatively connected to all the wheels 105, 110.

[0083] To maximize the comfort of the ATV riders (driver and passenger)and improve the dynamic behavior of the vehicle 100, the center ofgravity of the riders and vehicle 100 should be located properly. Toachieve this maximum comfort, the riders (driver and passenger) shouldbe located as close as possible to the center of the wheelbase L. Thispositioning enables the riders to naturally pivot between the front andrear wheels 105, 110 and experience as little jostling forces aspossible during operation of the ATV 100. The comfort provided by suchpassenger positioning is best illustrated with reference to a schoolbus, in which a person sitting in the back of the bus is far away fromthe bus's wheelbase center and experiences significant jostling as thebus pivots over bumps. Accordingly, the combined center of gravity ofthe vehicle, driver, and passenger should each be close to the center ofthe wheelbase L of the ATV 100 in order to obtain dynamic behavior thatis as neutral as possible.

[0084]FIG. 8 comparatively illustrates the centers of gravity of anexemplary ATV 100, driver, and passenger relative to the centers ofgravity of (1) the conventional ATV 1000, its driver, and anunauthorized passenger (as shown in FIGS. 11A and 11B), and (2) theconventional ATV 1000, its driver, and a passenger sitting in the aftermarket passenger seat 1100 (as shown in FIGS. 12A and 12B). Allpositions are shown relative to the rear axis of the relevant ATV 100,1000. The exemplary ATV 100 is shown in phantom to provide perspectiveto the various positions. In the exemplary ATV 100 illustrated in FIG.8, the wheelbase L is about 61 inches, the distance R is about 25inches, the distance H is about 2 inches, the distance B is about ¾ ofan inch, and the distance S is about 37 inches (see dimensions in FIG.1).

[0085] As illustrated, an ATV 100 center of gravity 500 is horizontallydisposed in front of the axis 108 by a distance A_(xR), which ispreferably between 26 and 35 inches, is more preferably between 27 and34 inches, and is even more preferably about 29 inches. Conversely, acenter of gravity 510 of the ATV 1000 is only disposed 25 inches infront of the rear wheel axis 1070 (see FIG. 11A).

[0086] In one embodiment of the present invention, a ratio of ahorizontal distance A_(xR) between the rear axis 108 and the center ofgravity 500 of the ATV 100 to the distance L is preferably between 0.25and 0.75, is more preferably between 0.4 and 0.6, and is even morepreferably between about 0.45 and 0.55.

[0087] In an alternative embodiment of the present invention, a ratio ofa horizontal distance A_(xF) between the front axis 107 and the centerof gravity 500 of the ATV 100 to the distance A_(xR) (between the centerof gravity 500 and the rear axis 108), which equals the distance Ldivided by the distance A_(xR) minus one, is preferably between 1.05 and2, is more preferably greater than 1.07, is even more preferably greaterthan 1.09, is even more preferably greater than 1.1, and is even morepreferably about 1.12.

[0088] The center of gravity 500 is disposed above the rear wheel axis108 by a distance A_(y), which is preferably between about 0 and 10inches, and is more preferably about 7 inches. In an alternativeembodiment, the distance A_(y) is about 5 inches.

[0089] As illustrated in FIG. 9, an angle α_(R) is formed between thefront wheel axis 107, the rear wheel axis 108, and the center of gravity500. Similarly, an angle α_(F) is formed between the rear wheel axis108, the front wheel axis 107, and the center of gravity 500. The anglesα_(R) and α_(F) are preferably less than 20 degrees and more preferablyabout 15 degrees. The angle α_(R) may alternatively be about 10 degrees.The angle α_(F) may alternatively be about 9 degrees. A line that formsthe base of the angles α_(R), α_(F) and extends between the front andrear axes 107, 108 is preferably generally level because the front andrear wheels 105, 110 are preferably generally equally sized. In oneembodiment, the front wheel 105 has a 25 inch diameter while the rearwheel 110 has a 26 inch diameter.

[0090] As illustrated in FIG. 8, a center of gravity 520 of the driversitting on the main seat portion 140 of the ATV 100 is horizontallydisposed in front of the axis 108 by a distance D_(xR), which ispreferably between 13 and 30 inches, is more preferably between 15 and30 inches, is even more preferably between 19 and 30 inches, and is evenmore preferably about 22 inches. Conversely, the driver on the ATV 1000without a passenger seat 1100, who is squished forwardly to providespace for the passenger 1020 as shown in FIG. 11A, has a center ofgravity 530 that is only disposed about 19 inches in front of the rearwheel axis 1070. Similarly a center of gravity 540 of the driver on theATV 1000 with the passenger seat 1100 (as shown in FIG. 12A) is onlydisposed about 12 inches in front of the axis 1070. Accordingly, FIG. 8illustrates that the elongation of the frame 102 and wheelbase L of theATV 100 enable the driver on the ATV 100 to be positioned farther infront of the rear wheel axis 108 than on conventional ATVs.

[0091] The center of gravity 520 is disposed above the rear wheel axis108 by a distance D_(y), which is preferably between about 10 and 35inches, is more preferably between 15 and 35 inches, and is even morepreferably about 22 inches.

[0092] As illustrated in FIG. 9, an angle δ_(R) is formed between thefront wheel axis 107, the rear wheel axis 108, and the center of gravity520. An angle δ_(F) is formed between the rear wheel axis 108, the frontwheel axis 107, and the center of gravity 520. The angles δ_(R) andδ_(F) are preferably between 30 and 60 degrees, are more preferablybetween 30 and 51 degrees, and are even more preferably about 45degrees. In an alternative embodiment, the angle δ_(F) is preferablybetween 15 and 45 degrees, is more preferably between 15 and 33 degrees,and is even more preferably about 32 degrees.

[0093] A center of gravity 550 of the passenger sitting on the secondaryseat portion 145 of the ATV 100 is horizontally disposed in front of therear axis 108 by a distance P_(xR), which is preferably greater thanzero, is more preferably between 1 and 19 inches, is even morepreferably between 4 and 15 inches, and is even more preferably about 7inches. Conversely, a center of gravity 560 of the unauthorizedpassenger on the ATV 1000 without the passenger seat (as shown in FIG.11A) is only disposed about 4 inches in front of the rear axis 1070. Acenter of gravity 570 of the passenger on the passenger seat 1100 (asshown in FIG. 12A) is actually disposed behind the rear axis 1070 byabout 6 inches. Accordingly, FIG. 8 illustrates that the elongation ofthe frame 102 and wheelbase L and the positioning of the secondary seatportion 145 enable the passenger on the ATV 100 to be disposed fartherforward on the ATV 100 than on conventional ATVs. Such positioningimproves the stability and comfort of the passenger on the ATV 100.

[0094] A ratio of a distance P_(xF) between the front axis 107 and thecenter of gravity 550 of the passenger on the ATV 100 to the distanceP_(xR) (between the center of gravity 550 and the rear axis 108), whichequals the distance L divided by the distance P_(xR) minus one, ispreferably between 2 and 13, is more preferably between 2 and 11, iseven more preferably between 2 and 9, and is even more preferably about8. Similarly, a ratio of the distance between the front axis 107 andcenter of the secondary supporting range 145 b to the distance betweenthe center of the secondary supporting range 145 b and the rear axis 108is preferably between 2 and 50, is more preferably between 2 and 40, iseven more preferably between 2 and 30, and is even more preferablybetween 10 and 20.

[0095] The center of gravity 550 is disposed above the rear wheel axis108 by a distance P_(y), which is preferably between about 20 and 40inches, and is more preferably about 27 inches.

[0096] As illustrated in FIG. 9, an angle π_(R) is formed between thefront wheel axis 107, the rear wheel axis 108, and the center of gravity550. The angle π_(R) is preferably between 60 and 90 degrees, is morepreferably between 70 and 80 degrees, and is even more preferably about76 degrees. An angle π_(F) is formed between the rear wheel axis 108,the front wheel axis 107, and the center of gravity 550. The angle π_(F)is preferably between 15 and 45 degrees, is more preferably between 15and 30 degrees, and is even more preferably about 27 degrees.

[0097] When both a driver and a passenger ride the ATV 100, a combinedcenter of gravity 580 of the ATV 100 and the two riders is horizontallydisposed in front of the rear axis 108 by about 25 inches. Conversely,when two riders ride the ATV 1000 without a passenger seat 1100 (asshown in FIG. 11A), a combined center of gravity 590 is only disposedabout 21 inches in front of the rear axis 1070. Similarly, when tworiders ride the ATV 1000 with a passenger seat 1100 (as shown in FIG.12A), a combined center of gravity 600 is only disposed about 19 inchesin front of the rear axis 1070.

[0098] Similarly, the combined center of gravity 580 is preferablydisposed rearwardly of the front axis 107 by a distance C_(xF) that ispreferably between 25 and 50 inches, is more preferably between 30 and45 inches, is even more preferably between 33 and 45 inches, is evenmore preferably between 34 and 45 inches, and is even more preferablyabout 36 inches.

[0099] The combined center of gravity 580 is preferably disposed abovethe rear wheel axis 108 by a distance C_(y), which is preferably between5 and 20 inches, and is more preferably by about 11 inches.

[0100] As illustrated in FIG. 9, an angle κ_(R) is formed between thefront wheel axis 107, the rear wheel axis 108, and the combined centerof gravity 580. The angle κ_(R) is preferably between 15 and 45 degrees,is more preferably between 15 and 35 degrees, and is even morepreferably about 30 degrees. In an alternative embodiment, the angleκ_(R) is preferably between 15 and 30 degrees, is more preferablybetween 15 and 25 degrees, and is even more preferably about 24 degrees.An angle κ_(F) is formed between the rear wheel axis 108, the frontwheel axis 107, and the combined center of gravity 580. The angle κ_(F)is preferably between 10 and 45 degrees, is more preferably between 10and 30 degrees, is even more preferably between 15 and 30 degrees, andis even more preferably about 20 degrees. In an alternative embodiment,the angle κ_(F) is preferably between 10 and 18 degrees, and is morepreferably about 17 degrees.

[0101] As illustrated in FIGS. 1, 6, and 9, the power unit 215 islocated in front of the rear wheel axis 108 by a distance E. Thedistance E is preferably about 22 to 40 inches and is more preferablyabout 24 to 38 inches. In an alternative embodiment, the distance E ispreferably about 22-30 inches, and is more preferably about 24-27inches. Because the power unit 215 is preferably disposed at generallythe same longitudinal position on the ATV 100 as the main supportingrange 140 b, the distances E plus T equal the wheelbase L. However, sucha relationship between the power unit 215 and the main supporting range140 b is not required. Furthermore, a ratio of the distance E to thedistance L is preferably between 0.25 and 0.75 and is more preferablybetween 0.4 and 0.6.

[0102] The centers of gravity of the riders are measured when the ridersare seated on their respective seat portions in standard ridingpositions. As would be appreciated by those of ordinary skill in theart, when in a standard riding position, the driver's feet are placed onthe footrests, the driver is sitting on the seat portion 140, and thedriver's hands are grabbing the handlebars 134 of other steering device.Similarly, the passenger's feet are placed on the footrests, thepassenger is sitting on the seat portion 145, and the passenger's handsare holding onto the passenger grab handles, if provided. The standarddriver and passenger have the weight and dimensions of a 50^(th)percentile human male, which are illustrated in FIGS. 13 and 14.

[0103] Because the power unit 215, which is among the heaviestcomponents on the ATV 100, is disposed in front of the rear axis 108 bythe distance E, and the wheelbase L of the ATV 100 is longer than onconventional ATVs, the center of gravity 500 of the ATV 100 is shiftedproportionally rearwardly relative to wheelbases of conventional ATVs.Accordingly, the center of gravity 500 of the ATV 100 is shiftedrearwardly and is therefore closer to the main and secondary supportingranges 140 b, 145 b (and consequently closer to the centers of gravity520, 550 of the riders) than on conventional ATVs. Also, while the powerunit is typically disposed in front of the driver seat in conventionalATVs, a forward end of the power unit 215 is preferably disposedlongitudinally rearwardly from the forward end 140 a of the main seatportion 140 of the ATV 100.

[0104] To optimize the comfort of the riders and the dynamic performanceof the ATV 100, the combined center of gravity 580 should be as centeredon the wheelbase L as possible. If the center of gravity of the vehicle500 is centered on the wheelbase L, the center of gravity of the driver520 and the passenger 550 should be as close to the center of thewheelbase L as possible. Because it is difficult to simultaneouslycenter each of the driver, passenger, and ATV 100 on the wheelbase L,the ATV 100 should be designed so that the center the combined center ofgravity 580 is positioned as close to the center of the wheelbase L aspossible. It is anticipated that a single rider (the driver) will ridethe ATV 100 about 70% of the time and two riders (the driver and thepassenger) will ride the ATV about 30% of the time. Accordingly, thecenter of gravity 500 of the ATV 100 is preferably positioned such thatwhen a combined center of gravity 580 is determined using apercentage-of-use-based weighted average of the positions and weights ofthe driver and passenger, the combined center of gravity 580 ispositioned as close to the center of the wheelbase L as possible.

[0105] In an alternative embodiment of the present invention, thedynamic characteristics of the ATV 100 and comfort of the driver andpassenger may be improved by positioning the center of gravity 500 ofthe ATV 100 as close as possible to the centers of gravity 520, 550 ofthe riders. To accomplish this, the center of gravity 500 of the ATV 100could be moved part way between the centers of gravity 520, 550 of thedriver and passenger with the exact placement of the center of gravity500 being determined by the weighted average of the percentage of use ofthe ATV 100 in one-rider and two-rider modes. The main and secondarysupporting ranges 140 b, 145 b are reasonably close to the longitudinalpositions of the centers of gravity 520, 550 of the driver andpassenger, respectively, when riding the ATV 100. Accordingly, thecenters of the supporting ranges 140 b, 145 b will be used herein asreference points for describing the placement of the center of gravity500 of the ATV 100. In other embodiments, the centers of gravity 520,550 are disposed in front of the centers of the supporting ranges 140 b,145 b by between about 2 and 5 inches. Similarly, the centers of gravity520, 550 are disposed above the centers of the supporting ranges 140 b,145 b by several inches (e.g., 4-6 inches).

[0106] In this alternative embodiment, the center of gravity 500 of theATV 100 is preferably longitudinally positioned between the supportingranges 140 b, 145 b, and is more preferably disposed rearwardly of themain supporting range 140 b by about 30% of the distance Q between thecenters of the supporting ranges 140 b, 145 b. The center of gravity ofthe ATV 100 is preferably disposed closer to the main supporting range140 b than to the secondary supporting range 145 b because a driverrides the ATV 100 70% more often than a passenger. In this alternativeembodiment, the power unit 215 may be shifted further rearward in orderto shift the center of gravity 500 of the ATV 100 farther rearward.

[0107] In conventional ATVs, a hydraulic brake actuating system istypically provided rearwardly of the power unit. Such positioning isconvenient because it is close enough to the footrest to convenientlyprovide a mechanical connection between a foot brake pedal and thehydraulic brake actuating system. Conversely, in the ATV 100, a front(or main) footrest portion 260 of a footrest 250 of the ATV 100, whichis described in greater detail below, is disposed in front of the powerunit 215, which places the front foot rest portion 260 well forward ofthe conventional position of the hydraulic brake actuating system.

[0108] Accordingly, to simplify the mechanical connection between thefoot brake pedal and the hydraulic brake actuating system, a hydraulicbrake actuating system 217 of the ATV 100 is disposed in front of thepower unit 215 (see FIGS. 6 and 7). As best shown in FIG. 7, the system217 includes a master cylinder 220 operatively connected via hydrauliclines 221 to conventional hydraulic brakes (not shown) that areconnected to one or more of the wheels 105, 110. The master cylinder 220includes mating cylinder and piston portions 220 a, 220 b. An axis ofthe master cylinder 220 extends in a direction that is generallyperpendicular to the longitudinal direction of the ATV 100. As best seenin FIG. 6, the master cylinder 220 is angled slightly downwardly suchthat the piston portion 220 b is disposed below the cylinder portion 220a. The cylinder portion 220 a is mounted (via bolts or other fasteners)to a portion of the frame 102.

[0109] A swing arm 223 is also pivotably connected at a first end 223 ato the frame 102 for relative pivotal movement about a swing arm axis224 that extends in the longitudinal direction of the ATV 100. A secondend 223 b of the swing arm 223 is pivotably connected to the pistonportion 220 b such that pivotal movement of the swing arm 223 actuatesthe master cylinder 220. A hand brake lever 226 (see FIG. 1) isoperatively connected to the second end 223 b of the swing arm 223 via aflexible sheathed cable 225 (see FIG. 7). A laterally-extending footbrake 227 attaches (preferably via a weld) to the first end 223 a of theswing arm 223 for common pivotal movement about the swing arm axis 224relative to the frame 102. As illustrated in FIGS. 6 and 7, the footbrake 227 includes a foot pedal 227 a that is conveniently disposedabove a right, front portion 260 of a right footrest 250. A tensionspring 228 connects between the foot brake 227 and a portion of theframe 102 to bias the foot brake 227 upwardly and thereby bias thesecond end 223 b and piston portion 220 b to the left as illustrated inFIG. 7.

[0110] As shown in FIG. 7, to actuate the brakes of the ATV 100, thedriver can either squeeze the hand brake 226 or depress the foot pedal227 a to move the second end 223 b of the swing arm 223 to the right,move the piston portion 220 b to the right, and contract the mastercylinder 220. When the driver releases the hand and foot brakes 226,227, the spring 228 pulls the foot brake 227 upwardly, which pushes thesecond end 223 b of the swing arm 223 back to the left to extend themaster cylinder 220 and release the brakes.

[0111] As illustrated in FIG. 6, the longitudinal elongation of theframe 102 enables ATV 100 components such as the power unit 215, brakeactuating system 217, batteries, etc. to be longitudinally spaced fromeach other to a greater extent than in conventional ATVs. Inconventional ATVs, the lack of longitudinal space forces designers tostack ATV components into longitudinally cramped locations. Conversely,as is apparent in FIG. 6, the longitudinal elongation of ATV 100 allowscomponents to be spread out over the longer length of the frame 102 ofthe ATV 100. The longitudinal spacing makes access to individualcomponents such as the brake actuating system 217 (see FIGS. 6 and 7)much simpler. By simply removing the removable seat 139, which isremovably connected to the ATV 100 using conventional fasteners (e.g., alatch, etc.), an operator can access many of the components of the ATV100 for necessary maintenance and/or servicing. Otherwise, the space canbe used for additional storage.

[0112] Each of the rear fenders 137 includes a series of ventilationopenings 230 that direct air to the air intake of the power unit 215and/or a radiator/fan assembly (not shown). Additional ventilationopenings 235 are provided for the power unit 215 below the forward end140 a of the main seat portion 140 a.

[0113] As illustrated in FIGS. 1, 3A, 5, and 6, the ATV 100 includesleft and right footrests 250, which include front portions 260 for thedriver sitting on the main seat portion 140 and rear portions 270 forthe passenger sitting on the secondary seat portion 145. As illustratedin FIGS. 5A-5C, the front and rear portions 260, 270 preferably includeupper surfaces 260 a, 270 a that are each generally horizontal andinclude anti-slip surface treatments. However, the upper surfaces 260 a,270 a may alternatively be angled forwardly or rearwardly. The front andrear footrest portions 260, 270 preferably include respective heel stops280, 290 that extend upwardly from the upper surfaces 260 a, 270 a.

[0114] The upper surface 270 a of the rear footrest portion 270 iselevated relative to the upper surface 260 a of the front footrestportion 260 by a vertical distance X, which preferably approximates thevertical distance H formed between the seat portions 140, 145. However,the distance X may alternatively be larger than the distance H such thatan average sized passenger sitting on the secondary seat portion 145must bend his/her legs to a greater extent than the driver who sits onthe main seat portion 140. In such an embodiment, the distance X ispreferably between 1 and 10 inches, is more preferably between 3 and 8inches, is even more preferably between 3 and 7 inches, is even morepreferably between 4 and 6 inches, and is even more preferably about 5inches. The larger distance X also advantageously accommodates apassenger who is smaller than the driver.

[0115] As best illustrated in FIGS. 5A-5C, the rear footrest portion 270preferably comprises a plurality of sheets of material that connecttogether to elevate the upper surface 270 a relative to the uppersurface 260 a. The upper surface 270 a is defined by an upper sheetmember 270 d of the rear footrest portion 270. The footrest portion 270also includes a front, generally-planar, sheet member 270 b, whichextends vertically from a forward edge of the upper sheet member 270 dto an upper rear edge of the front footrest portion 260. A side,generally-planar, sheet member 270 c extends vertically from an outerlateral edge of the upper sheet member 270 d to a side guard 300, whichis described in greater detail below. The sheet members 270 b, 270 c,270 d preferably comprise sheet metal and may include holes and/oropenings to reduce their weight without significantly adverselyaffecting their strength. The separate members 270 b, 270 c, 270 d maybe integrally formed by bending a unitary sheet of material, or mayalternatively be welded, glued, bolted, or otherwise fastened together.

[0116] As best illustrated in FIG. 5A, the footrests 250 preferablyextend over a full longitudinal distance F formed between thefenders/mudguards 135, 137. Because the wheelbase L of the ATV 100 issignificantly longer than in conventional ATVs, the distance F betweenthe fenders 135, 137 is also significantly longer than in conventionalATVs. The length F is preferably as large or larger than twoaverage-sized shoes lined up end to end. Accordingly, the length F ispreferably between 17 and 40 inches, is more preferably between 20 and40 inches, is even more preferably between 25 and 35 inches, and is evenmore preferably about 30 inches. Such a length F allows the driver andpassenger to both use the footrests 250 without interfering with eachother's feet. Similarly, a ratio of the wheelbase L to the length F ispreferably between 1 and 2.7, is more preferably less than 2.6, is evenmore preferably less than 2.5, and is even more preferably about 2.

[0117] As illustrated in FIGS. 1 and 5, right and left side guards (orside bumpers or tree guards or side rails) 300 preferably extendlaterally outwardly from the frame 102 and/or footrests 250 to positionsthat are laterally outward from the outer lateral ends of the footrests250. The side guards 300 preferably extend longitudinally from a forwardend of the front footrest portion 260 to a rearward end of the rearwardfootrest portion 270. At least a portion of the side guards 300 alsopreferably extends laterally outwardly beyond the rear fenders 137. Asbest illustrated in FIGS. 5B and 5C, a middle portion of each side guard300 angles laterally outwardly and upwardly as it progresses rearwardly.The illustrated side guards 300 provide support for the footrests 250.Accordingly, the upward angle of the middle portion of the side guards300 preferably creates at least a portion of the gap X between the frontand rear portions 260, 270 of the footrests 250. However, the sideguards 300 and footrests 250 may alternatively be completely distinct.

[0118] Each of the illustrated side guards 300 preferably comprisesstrong, metallic, unitary, tubular members. The unitary member may be acomposite of integrally connection sections. The integral connectionbetween sections of each side guard 300 may be formed by welding,gluing, or using any other comparable permanent attachment mechanism.Alternatively, the unitary member may result from integral formation,such as would be the case if each side guard comprised a single,elongated, tubular member.

[0119] Each of the illustrated side guards 300 are designed to withstandan impact with a tree or other stationary object during operation of theATV 100. If the driver steers the ATV 100 too close to a stationaryobject, the side guards 300 will contact the object and deflect the ATV100 away from the object to prevent the object from squeezing laterallyagainst and/or breaking fragile components of either the ATV 100 (e.g.,the fenders 135, 137, the rear rack 130, or the grab handles 340) or,more importantly, the riders' arms and legs.

[0120] An open space 330 is provided in front of the main portion 140 ofthe seat 139. The open space 330 is provided to facilitate entry andexit from the ATV 100, as described in commonly assigned U.S.application Ser. No. 09/057,652, filed on Apr. 9, 1998, which isincorporated herein by reference in its entirety. Alternatively, theopen space 330 could be provided just behind the main seat portion 140and just in front of the secondary seat portion 145. Of course, an openspace could be provided in front of the main portion 140 and in front ofthe secondary portion 145, to facilitate ingress/agress of both thedriver and passenger. Alternatively, the open space 330 could be omittedentirely without deviating from the scope of the present invention.

[0121] As illustrated in FIGS. 1-3B, 3D, and 4A-4C, right and left grabhandles 340 are provided on the right and left lateral sides of thesecondary seat portion 145 to help the passenger sitting on thesecondary seat portion 145 stabilize himself/herself during operation ofthe ATV 100. As best illustrated in FIGS. 3A and 4B, the grab handles340 preferably do not extend laterally outwardly beyond the side guards300 or the side members 130 b of the rear rack 130. The illustrated grabhandles 340 attach to and are supported by the rear rack 130, but mayalternatively attach to any other suitable portion of the ATV 100 (e.g.,directly to the frame, etc.). The grab handles 340 extend forwardly froma forward portion of the rear rack 130. In the illustrated embodiment,the grab handles 340 are clamped to the rear rack 130 with bolts 342 butmay alternatively be attached to the rear rack 130 using a variety ofother attachment techniques (e.g., integral formation with the rearrack, glue, direct bolts, welds, etc.). As illustrated in FIGS. 1 and4A, the grab handles 340 are positioned at roughly the same longitudinalposition as the secondary supporting range 145 b of the secondary seatportion 145 to provide the passenger with easy access to the grabhandles 340. Further, the grab handles 340 are preferably convenientlydisposed at about the same height as the secondary supporting range 145b. Accordingly, while the grab handles 340 are high enough that thepassenger can easily reach them while seated on the secondary seatportion 145, the grab handles 340 are low enough that they do notsignificantly interfere, if at all, with the lateral movement of thepassenger's legs or with the passenger's ability to mount and dismountthe ATV 100. Consequently, if the ATV 100 happens to roll over, the grabhandles 340 will not trap the passenger on the ATV 100. Furthermore, thecombination of physical freedom and support that the grab handles 340provide the passenger help to enable the passenger to comfortably andactively position himself/herself while riding the ATV 100.

[0122] As best illustrated in FIGS. 4B and 4C, the grab handle 340preferably includes a ring-shaped portion 340 a that provides a varietyof gripping portions that the passenger can easily, firmly grip withhis/her hands. The grab handle 340 may also include a gripping knob 340b disposed within the opening inside the ring-shaped portion 340 a. Thepassenger may grab onto the gripping knob 340 b or the ring-shapedportion 340 a to help stabilize and actively position himself/herself onthe ATV 100 while riding. If the passenger uses the gripping knob 340 binstead of the ring-shaped portion 340 a of the grab handle 340, thering-shaped portion 340 a may function as a hand guard to prevent thepassenger's hands from hitting objects such as branches that the ATV 100brushes by during operation. While the illustrated grab handle 340includes a ring-shaped portion 340 a and a gripping knob 340 b, avariety of alternatively shaped grab handles may also be used withoutdeviating from the scope of the present invention.

[0123] The ring-shaped portion 340 a of the grab handle 340 ispreferably flexible enough that it can deform when a passenger dismountsthe secondary seat portion 145 and yet rigid enough that the ring-shapedportion 340 a can provide sufficient support for the passenger. The grabhandles 340 preferably comprise metal portions that are covered with aresilient material such as rubber or plastic. The ring-shaped portion340 a may be blow molded and hollow so that it provides the neededflexibility and strength. The ring-shaped portion 340 a preferablycomprises a resilient material such as rubber or plastic. The resilientmaterial preferably provides a more comfortable grip for the passengerthan a hardened, purely metal, grab handle.

[0124] The grab handles 340 may be heated to provide the passenger withadded comfort during cold weather use. Electric heating elements (notshown) may be mounted to or in the grab handles 340 and operativelyconnected to the ATV's electrical system so as to provide the desiredelectric heating.

[0125] While the illustrated grab handles 340 extend generallyhorizontally (i.e., their horizontal component is substantially greaterthan their vertical component) on the ATV 100, the grab handles 340could alternatively extend upwardly on either side of the secondary seatportion 245. The location and orientation of such grab handles may besimilar to the grab handles described in commonly assigned U.S.Provisional Application Serial No. 60/354,968, titled “QUICK RELEASEPASSENGER SEAT WITH FLEXIBLE GRAB HANDLE,” filed on Feb. 11, 2002, whichis incorporated herein by reference in its entirety. Such grab handlesmay still be mounted to the rear rack 130 or to the top of the rearfenders 137.

[0126]FIG. 10 illustrates alternative grab handles 344 that may replacethe grab handles 340. The grab handles 344 each comprise generallyU-shaped, tubular members 346. The ends of the U-shaped members 346extend rearwardly and attach to the front end of the rear rack 130 viabolts, welds, etc. The tubular members 346 may comprise metal tubes. Theforward portion of the U-shaped members 346 are preferably covered witha non-slip coating such as a resilient rubber cover 348 that enables thepassenger to comfortably and securely grip the grab handles 344.

[0127] A gear shift 350 is provided on the left hand of the steeringcolumn of the handlebars 134. The gear shift 350 is movable betweenvarious positions, including a park position (P), neutral (N), drive (H,L) and reverse (R).

[0128] As illustrated in FIG. 15, the two-person ATV 100 may be modifiedto accommodate three or even more riders on an ATV 400. The two-personATV 100 may be converted into the three-person ATV 400 by adding alongitudinal extension to the ATV 100 between the main and secondaryseat portions 145. Accordingly, a seat 405 of the ATV 400 includes amain seat portion 410 for a driver, a secondary seat portion 420 for afirst passenger, and a tertiary seat portion 430 for a second passenger.For each additional rider to be added, the wheelbase L, the length F,and the length S should each be increased (e.g., by 8 to 15 inches perrider). The lateral distance between the wheels 105, 110 should be setto give comfort and stability to the vehicle. Furthermore, for eachadditional passenger, the straddle-type seat 139 should include anadditional passenger seat portion and the footrests 250 should includean additional, appropriately positioned footrest portion. The power unit215 would be longitudinally positioned to optimize the ATV's center ofgravity based on a weighted average of the proportional occupancy timefor each seat portion.

[0129] While the preferred embodiments include many features, the scopeof the present invention is not limited to the combination of every oneof the features. Rather, the invention may comprise any combination ofone or more of these features (e.g., elongated wheelbase, improved ATVcenter of gravity, centrally located brake actuating system, passengerseat, passenger seat positioning, driver seat, driver seat positioning,backrest, elongated and/or stepped footrests, side grab handles, lowpassenger positioning, tapering driver and passenger seat portions, sideguards, open storage space on top of the rear rack, facilitation ofactive positioning for the driver and/or passenger, etc.).

[0130] While preferred embodiments have been discussed with reference tospecific features therein, it is to be understood that the preferredembodiments are examples only and that other preferred embodiments wouldbe apparent to those of ordinary skill in the art without fallingoutside the spirit and scope of the present invention.

What is claimed is:
 1. An ATV comprising: a frame; only four wheelssuspended from the frame, two of which are rear wheels and two of whichare front wheels, the front wheels defining a front axis and the rearwheels defining a rear axis, the front axis and the rear axis defining awheelbase between 52 to 72 inches, and each of the wheels includes anATV-type tire; a power unit for driving at least one of the wheelsdisposed on the frame; a straddle-type seat supported by the frameincluding a main seat portion for a driver and a secondary seat portion,rearward of the main portion, for a passenger; and a steering memberconnected to the frame comprising a handlebar for steering at least oneof the wheels, wherein the straddle-type seat is constructed andarranged such that, in use, a combined center of gravity of the ATV,with the driver sitting in a standard riding position on the main seatportion and the passenger sitting in a standard riding position on thesecondary seat portion, is disposed in front of the rear axis by atleast 22 inches.
 2. The ATV of claim 1, wherein the straddle-type seatis constructed and arranged such that, in use, the center of gravity isdisposed in front of the rear axis by at least 23 inches.
 3. The ATV ofclaim 2 wherein the straddle-type seat is constructed and arranged suchthat, in use, the center of gravity is disposed in front of the rearaxis by at least 24 inches.
 4. An ATV comprising: a frame; only fourwheels suspended from the frame, at least one of which is a front wheeland at least one of which is a rear wheel, the front wheel defining afront axis and the rear wheel defining a rear axis; a power unit fordriving at least one of the wheels disposed on the frame; astraddle-type seat supported by the frame including a main seat portionfor a driver and a secondary seat portion, rearward of the main portion,for a passenger; and a steering member connected to the frame comprisinga handlebar for steering at least one of the wheels, wherein thestraddle-type seat is constructed and arranged such that, in use, acombined center of gravity of the ATV, with the driver sitting in astandard riding position on the main seat portion and the passengersitting in a standard riding position on the secondary seat portion, isdisposed rearwardly of the front axis by at least 21 inches.
 5. The ATVof claim 4, wherein the straddle-type seat is constructed and arrangedsuch that, in use, the center of gravity is disposed rearwardly of thefront axis by at least 22 inches.
 6. The ATV of claim 5, wherein thestraddle-type seat is constructed and arranged such that, in use, thecenter of gravity is disposed rearwardly of the front axis by at least23 inches.
 7. The ATV of claim 6, wherein the straddle-type seat isconstructed and arranged such that, in use, the center of gravity isdisposed rearwardly of the front axis by between 24 and 45 inches. 8.The ATV of claim 4, wherein the straddle-type seat is constructed andarranged such that, in use, the center of gravity is disposed in frontof the rear axis by at least 30 inches.
 9. The ATV of claim 8, whereinthe straddle-type seat is constructed and arranged such that, in use,the center of gravity is disposed in front of the rear axis by at least32 inches.
 10. The ATV of claim 9, wherein the straddle-type seat isconstructed and arranged such that, in use, the center of gravity isdisposed in front of the rear axis by at least 33 inches.
 11. The ATV ofclaim 10, wherein the straddle-type seat is constructed and arrangedsuch that, in use, the center of gravity is disposed in front of therear axis by between 34 and 45 inches.
 12. An ATV comprising: a frame;only four wheels suspended from the frame, two of the which are rearwheels and two of which are front wheels, the front wheels defining afront axis and the rear wheels defining a rear axis, and each of thewheels includes an ATV-type tire; a power unit for driving at least oneof the wheels disposed on the frame; a straddle-type seat supported bythe frame including a main seat portion for a driver and a secondaryseat portion for the passenger; and a steering member connected to theframe comprising a handlebar for steering at least one of the wheels,wherein the ATV has a center of gravity, and wherein a ratio of adistance between the front axis and the center of gravity to a distancebetween the center of gravity and the rear axis is greater than 1.05.13. The ATV of claim 12, wherein the ratio is greater than 1.07.
 14. TheATV of claim 13, wherein the ratio is greater than 1.09.
 15. The ATV ofclaim 14, wherein the ratio is greater than 1.1.
 16. The ATV of claim15, wherein the ratio is greater than 1.11.
 17. The ATV of claim 12,wherein the ratio is between 1.05 and 2.